Cochlear Implantation in Children with Congenital Inner Ear Malformations

Objective/Hypothesis: To assess the audiologic and surgical outcomes for pediatric cochlear implant patients with inner ear malformations.

Study Design: Retrospective review of 315 pediatric cochlear implant cases from 1994 to 2002.

Methods: Twenty-eight pediatric cochlear implant patients with known inner ear malformations determined on high-resolution computed tomography (HRCT) of the temporal bone were the subjects of review. Results ofHRCTfindings, intraoperative findings, postoperative complications, and objective measures of both closed- and open-set testing of speech perception were analyzed.

Results: Patients with the constellation of an incompletely partitioned (IP) cochlea, enlarged vestibular aqueduct (EVA), and a dilated vestibule (i.e., Mondini's malformation) as well as those with an isolated EVA or partial semicircular canal aplasia have relatively good levels of speech perception. Patients with total semicircular canal aplasia, isolated IP, cochlear hypoplasia, or common cavity demonstrated lower levels of performance. Poor performance may be related to associated developmental delays rather than labyrinthine anatomy alone. Complications of surgery were relatively limited.

Conclusions: Cochlear implantation can be successfully performed in children with inner ear malformations. These children and their parents can expect significant auditory benefits from this intervention. The various types of inner ear malformations may have quite different prognoses for good auditory performance.